Letters and Numbers

Privacy policy

Effective from: 13 September 2026  ·  Last updated: 13 September 2026

The app "Letters and Numbers" (on Google Play: "Learn to Write: ABC and 123") teaches children aged 4 to 7 to write letters and numbers. It is meant to be used under the supervision of a parent or carer. The app requires no account and collects no data that directly identifies you or your child (no names, email addresses, phone numbers or location). It processes only the technical identifiers and usage statistics described in section 2.

1. Who is responsible for your data

The joint data controllers, with an equal share in the project, are:

• Sebastian Rosiński — sebastian.rosinski.1989@gmail.com
• Dawid Adamczyk — phantom0492@gmail.com

You can send a request about your data to either address. In line with Article 26 of the GDPR, we inform you that we carry out our data protection duties jointly: whichever of us receives a request first answers it, and we handle breach reports together.

2. What data we process

The Firebase instance identifier is not linked to any person. It is assigned to the app on the device and changes when the app is uninstalled or its data is cleared.

3. Protecting children

• The app shows no ads. None, in any form.
• We use no personalised advertising and no behavioural profiling.
• We do not link data from this app with data from other apps or services.
• We do not pass data to third parties for marketing purposes and we do not sell it.
• Every purchase must be confirmed by an adult. Before payment the app asks a maths question that a child aged 4 to 7 cannot solve.
• The parent panel is protected by a PIN, which we store only in hashed form (never as plain text).

We act in accordance with the US COPPA act, Article 8 of the GDPR and the Google Play Families programme policies.

4. External services

5. In-app purchases

• The full version is unlocked by a one-time purchase. There is no subscription and no automatic renewal.
• We do not store payment card or bank details. Payment is handled entirely by Google Play.
• After reinstalling, the purchase can be restored with the "Restore purchase" button in the parent panel.
• Refunds are handled by Google Play under its own terms.

6. How long we keep data

• Learning progress and settings: until the app is uninstalled or its data is cleared. They disappear together with the app.
• Statistical data: kept by Firebase Analytics according to the project settings, for a maximum of 14 months.
• Transaction data: for the period required by tax and accounting regulations.

7. Your rights

You have the right to request access to your data, its rectification, erasure or restriction of processing, to object to processing, and to lodge a complaint with a supervisory authority: the authority for your place of residence, or the Polish authority responsible for us, the President of the Personal Data Protection Office (Prezes Urzędu Ochrony Danych Osobowych, UODO), under Article 77 of the GDPR.

Because the app has no accounts, we cannot link statistical data to a specific person or device. The most effective way to remove data from the device is therefore to uninstall the app. Details are in the Deleting data section.

8. Changes to this policy

We will announce significant changes in the app's update notes on Google Play. The current version is always available at this address, with the date of the last change at the top of the page.

9. Contact

About the app

Your child learns to write letters and numbers by tracing a ghost shape on the screen with a finger. No rush, no countdown and no comparing with others.

What your child learns

The app supports three countries: Poland, Germany and Austria. The country chosen in the parent panel sets the alphabet, the handwriting style and the set of animals.

• Poland (the default): 35 capital and 35 lowercase letters of the Polish alphabet, including ą, ć, ę, ł, ń, ó, ś, ź, ż, with two Polish school handwriting styles to choose from
• Germany: 29 capital and 30 lowercase letters, including ä, ö, ü, ß, with six German school handwriting styles
• Austria: the same alphabet in the Austrian school script
• 10 digits from 0 to 9, the same in every country

Every character has a fixed stroke order and writing direction. The scripts and the order match what children are taught at school in the chosen country, so the app never argues with the exercise book.

How practice works

• Your child traces the shape with a finger and sees straight away whether the line stays on track.
• After finishing a character they get stars, for accuracy rather than speed.
• Every character has its own forest animal, which grows up in four stages as your child practises.
• All the animals earned wait in the Zoo, ready to be visited again.

Parent panel

The panel is protected by a PIN. It shows your child's progress (characters mastered, number of attempts, animals collected), the settings for line thickness and difficulty level, and the button for restoring a purchase.

Free version and full version

The free version lets your child practise the first letters and numbers, so you can check whether the app suits them. The full version, with every character and every animal, is unlocked by a one-time purchase with no subscription.

Authors

The app is made by Sebastian Rosiński and Dawid Adamczyk. It is part of the Kidalu series, which also includes the Polish reading app Reading by Syllables.

For teachers and early-years educators

Useful information if you are considering the app for a kindergarten, preschool, after-school club or therapeutic work.

Scope of the material

For Poland the app covers the full Polish alphabet in capital and lowercase forms (35 characters each, including the diacritic letters) and the digits 0 to 9. Every character has a defined stroke order and direction that follow the Polish calligraphic standards for school handwriting, with two styles to choose from.

The app also supports Germany (29 capital and 30 lowercase letters with ä, ö, ü, ß, six German school scripts) and Austria (the same alphabet in the Austrian school script). The country is switched in the parent panel; changing it changes the alphabet, the script and the set of animals.

Methodological basis

• Tracing: the child reproduces a model instead of drawing freely, and the app checks that the hand stays on the line.
• Stroke order is enforced, so the child does not build a wrong movement habit.
• No time pressure: there is no stopwatch and no limit on attempts. What is assessed is accuracy.
• Adjustable difficulty: how far the hand may stray from the trail is set in the parent panel, so the demands can be matched to the child's motor skills.

Working with a group

• The app works without an internet connection. All that is needed is a device with a touchscreen.
• It requires no account or sign-in, so there is no need to collect consent for creating children's accounts.
• It shows no ads and no promotional content.
• Progress is saved on the device, separately for each device. The app does not distinguish between several pupils on the same tablet.

Limitations worth knowing

The app is a graphomotor exercise on a screen and does not replace writing with a pencil in an exercise book. A screen offers none of the resistance that paper gives and does not shape the pencil grip. Treat it as a supplement to traditional exercises, not a substitute.

The app is not a diagnostic or therapeutic tool. It is not designed to detect writing difficulties and does not replace work with a specialist.

Purchasing for an institution

At present the app is available only through Google Play, with a one-time purchase that unlocks the full version on a given device. If you need a larger number of licences for your institution, write to us and we will work out a solution.

Write to us

Deleting data

The app has no user accounts, so there is no profile to close. Everything the app remembers about your child is stored on the device.

How to clear data without uninstalling

1. Open the Android Settings.
2. Go to Apps and choose Learn to Write: ABC and 123.
3. Open Storage and choose Clear data.

The app returns to its initial state. The full-version purchase is not lost: you can restore it with the "Restore purchase" button in the parent panel, because it is tied to your Google Play account rather than to the data in the app.

Statistical data

Feature usage statistics are collected under an app instance identifier that points to no person. The identifier ceases to exist when the app is uninstalled or its data is cleared, and events collected before that are deleted automatically after 14 months at most.

If you want us to delete statistical data sooner, write to us. We will need the approximate period of use and the device model in order to find the right events.

Purchase data

Purchase history is kept by Google Play and RevenueCat. We cannot delete it, because it is the basis of your right to the full version of the app and an accounting record. Matters concerning payments and refunds are handled by Google Play.

Submitting a request

Write to either of the addresses below. We reply within 30 days.